Pathuri, Sachin

Purpose To compare clinical outcomes between augmented subchondral drilling (aSCD) and nonsubchondral drilling (NoSCD) techniques, both using a cartilage scaffold, in the treatment of isolated patellar cartilage lesions. Methods A retrospective cohort study was conducted on patients who underwent surgical treatment for isolated patellar cartilage using either an aSCD technique (a subchondral drilling augmented with a particulated cartilage allograft scaffold or a flexible osteochondral allograft scaffold) or a NoSCD technique (a particulated juvenile articular cartilage scaffold or a flexible osteochondral allograft scaffold implanted without performing a subchondral drilling). Patients were included if they had a minimum 2‐year follow‐up and excluded if they underwent concomitant meniscal or ligamentous procedures. While tibial tubercle osteotomy (TTO) was commonly performed, it was not a strict inclusion criterion. All procedures were performed through arthrotomy with a standardized postoperative rehabilitation protocol. Clinical outcomes included International Knee Documentation Committee (IKDC) and Lysholm scores, reoperation rates, conversion to total knee arthroplasty, and complications. Results A total of 65 knees were included: 31 in the aSCD group and 34 in the NoSCD group, with a mean follow‐up of 50.4 months (range, 24‐88 months). In the aSCD group, particulated allograft cartilage hydrated with platelet‐rich plasma was used in 80.7% of cases and flexible osteochondral allograft in 19.3%, while the NoSCD group was treated with Cartiform (Arthrex) in 70.6% and particulated juvenile articular cartilage in 29.4% of cases. TTO was performed in 87.0% of aSCD and 91.2% of NoSCD cases. Average defect sizes were 3.7 cm 2 (aSCD) and 4.0 cm 2 (NoSCD). At final follow‐up, the NoSCD group had significantly better outcomes, with higher median IKDC scores (81.0 vs 74.0; P < .001) and median Lysholm scores (83.0 vs 77.0; P < .001). A significantly greater proportion of NoSCD patients exceeded the minimal clinically important difference for IKDC (100% vs 80.6%; P = .024) but not for Lysholm (97.1% vs 93.5%; P = .935) at final follow‐up. In multivariable regression adjusting for scaffold type, TTO, and defect size, aSCD remained a significant independent predictor of lower final IKDC (β = –8.97; P = .001) and Lysholm (β = –12.71; P < .001) scores. The aSCD group had a significantly higher rate of repeat surgery (45.2% vs 14.7%; P = .015). There was no significant difference in conversion to total knee arthroplasty between groups ( P = .432). Conclusions For the treatment of isolated patellar cartilage lesions, a nonsubchondral drilling technique with scaffolding was associated with improved patient‐reported outcomes and fewer complications compared to a subchondral drilling technique with scaffolding, although there was no difference in the rate of conversion to total knee arthroplasty. Level of Evidence Level III, retrospective comparative study.